In a system having a client server, a computer having a magnetic disk unit and the like is used as a client terminal. However, due to complicated business processes, recently, one user uses a plurality of computers and one computer is used for the business processes. As a result, along with complicating of software for the client terminal, management cost of the client terminal increases. Furthermore, a probability of data leakage becomes high because the client terminal includes a storage unit such as a magnetic disk unit. In this way, a system has been changing to combine terminals with a server. Such a terminal is diskless (which has no storage device such as the magnetic disk unit) or a write operation to the disk is forbidden (hereinafter, to be referred to as a thin client terminal), and the server stores data and executes an operating system (OS) and business applications (hereinafter, to be referred to as a thin client sever). In Japanese Patent Application No JP2006-16559, the applicant of the present patent application already proposed a session management method which allows the operating system on the thin client server side to be booted up and shut down by the thin client terminal.
The thin client server executes business applications that have been executed by the client terminals in the conventional system having a client server. Accordingly, the thin client server includes a client as an executing section (execution image) for every thin client terminal. An operating system, business applications, and data are installed for every connection from the thin client terminal. Since the thin client server generally manages a plurality of the thin client terminals, a plurality of clients operate on the same thin client server.
In such a thin client system, a user connects the thin client terminal with the client in the thin client server, and makes the client to execute the business application. The user supplies data and commands required for execution of the business application via the thin client terminal, and confirms the execution result of the business application on a monitor of the thin client terminal.
In this thin client system, as well as an authentication of the user using the thin client terminal, the connection management of the thin client terminal to the thin client server is implemented by using individuals such as the user and the thin client terminal as a key (for example, see Japanese Patent Application No. 2006-166559). When such a connection control method is employed, it is required to allocate one or more clients on the thin client server to one user and it is difficult to allocate a single client to a plurality of users or to share the single client by the users. In addition, when a failure occur in the thin client server, the thin client terminal which has been connected to one client on the thin client server cannot be connected with the thin client server until the server returns to a normal condition, resulting in suspension of a user business.
Unlike the conventional system with the client server, the client cannot be rebooted up at an optional timing by the user in the thin client system. As a result, the user cannot implement operations such as application of security patch for the business applications and software update, which require rebooting up of the client. Thus, a system administrator has a heavy burden because the system administrator must implement these operations.
In a conventional session management method between the thin client terminals and the thin client server, the management becomes complicated since connection definition of M×N combinations is required in an environment that M clients in a thin client server are shared by N persons. In addition, since there is no way by that the user can preliminarily know which client is in an unused state in actual operational situation, the user is required to search the unused client by sequentially testing the client when the user connects the thin client terminal to the thin client server. Furthermore, when an in-use client becomes out of control, the user must reboot up the client terminal after contacting the administrator and identifying the in-use client through checking logs by the administrator.